"We rolled out this update with 220 changes. There's a breaking bug. Where is it? We need to find out in the next 5 minutes, revert, and deploy. Otherwise we have to revert the whole thing- we're losing money."

Git doesn't really help with that. More granular deployments do, and if microservices help with more granular deployments, go for it.

My experience is that most devs don't even know how to use SVN correctly. I just had a conversation with someone waiting for me to finish something before they could branch. The idea that I could merge my change into their branch afterwards didn't occur to them.